1. Technical Field
This invention relates in general to telecommunications and, more particularly, to cross-connect matrix.
2. Description of the Related Art
Cross-connect switches are used to provide switching between long haul communication lines. Two different sets of circumstances can result in a cross-connect switch changing the connections between lines. A first set of circumstances, known as “provisioning” takes place responsive to the commands of an operator. Provisioning may include, for example, changes in connections when a new line is introduced to the communications network.
A second set of circumstances is known as “restoration.” Restoration is implemented to restore communications after a problem has been detected. For example, communications are generally transmitted over two (or more) redundant lines, a “working” line and a “protect” line. If the working line is cut, a failure in communications is detected and the cross-connect will switch to the protection line.
A change in the connection through a cross-connect switch involves breaking the current connection and creating a new connection. The timing requirements for restoration of a communication line are very strict. Generally, the restoration must occur within a time period on the order of 50 milliseconds. On the other hand, a switch due to provisioning can occur within a time period of a few seconds.
If the cross-connect switch is working in an optical network layer, an interruption due to a single impaired fiber will result in restoration requests from multiple channels. Therefore, the time constraints to create and break connections are even more onerous.
Therefore, a need has arisen for an improved method of servicing connections through a matrix.